wemos mini d1 4 Articles . Battery-Powered ESP8266 Sensor? Never Been Simpler. December 31, 2022 by Arya Voronova 23 Comments ... You have an ESP8266 board like the Wemos D1, ...

The PCB holds a Wemos D1 Mini connected to two relays that switch the two heating circuits. The D1 runs ESPhome and needs just a few lines of configuration to connect it to [Simon]’s home network.